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unsetenv

Remove environment variable

Since R2022b

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    Syntax

    unsetenv(varname)

    Description

    example

    unsetenv(varname) removes the operating system environment variable varname. If any elements in varname do not exist, then unsetenv has no effect.

    Examples

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    Open Live Script

    Create environment variable myVar, and then check that it exists.

    setenv("myVar","myValue");
isenv("myVar")
    ans = logical
   1

    Remove myVar, and then check that it no longer exists.

    unsetenv("myVar");
isenv("myVar")
    ans = logical
   0
    Open Live Script

    Create multiple environment variables, and then check that they exist.

    setenv(["Var1" "Var2" "Var3" "Var4"],["Val1" "Val2" "Val3" "Val4"]);
isenv(["Var1" "Var2"; "Var3" "Var4"])
    ans = 2x2 logical array

   1   1
   1   1

    Remove two of the environment variables using unsetenv, and then check that they no longer exist.

    unsetenv(["Var1" "Var4"]);
isenv(["Var1" "Var2"; "Var3" "Var4"])
    ans = 2x2 logical array

   0   1
   1   0

    You can also remove environment variables using setenv with missing. Change the value of one environment variable and remove another. 

    setenv(["Var2" "Var3"],["ValB" missing]);
isenv(["Var1" "Var2"; "Var3" "Var4"])
    ans = 2x2 logical array

   0   1
   0   0

    Input Arguments

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    Environment variable names, specified as a string scalar, character vector, string array, or cell array of character vectors.

    Example: "PATH"

    Version History

    Introduced in R2022b

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    See Also

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